This is a proposal to evaluate the feasibility of using an implantable and wireless microstimulation device for reducing orofacial pain. Each year almost one sixth of the US population seeks treatment for craniofacial pain. Temporomandibular joint disorders (TMD) are one of the biggest segments of facial pain. Current methods of treating orofacial pain include drugs, prosthetic devices, and electrical stimulation. Drug treatments have major side effects when used long term and prosthetic devices are often ineffective or have side effects. As a result, neurostimulation techniques such as transcutaneous and percutaneous electrical stimulation (TENS and PENS) have become popular alternative therapies. While TENS is mildly efficacious, PENS treatments seem to be far more efficacious. However, PENS is highly inconvenient and invasive, often leaving the patient unable to receive treatment when needed most. To address these weaknesses of current electro-stimulation therapy, MicroTransponder has developed a tiny implantable wireless microstimulator device (1mm diameter and less than 250 um thick) that may have the efficacy of PENS without any of the inconveniences. This device is powered and controlled by short range radio frequency identification technology (RFID). The device is capable of directly stimulating peripheral nerves and can be controlled by the patient to deliver therapeutic stimulation as needed. This device should be an inexpensive, safe, and convenient solution to patients with orofacial pain. Eventually, all patients who suffer from chronic pain of different origins may benefit from this device. To establish the effectiveness of this device in reducing orofacial pain, we will implant our microstimulators into the temporomandibular joint (TMJ) area of rats. Orofacial pain will be induced by injecting complete Freund's adjuvant (CFA) into the TMJ. We will then deliver therapeutic stimulation and evaluate the effects of this stimulation on spontaneous eating behavior in a well characterized rat model of TMJ. To consider this method effective for the treatment of pain, we must observe a statistically significant reduction in pain behavior in this animal model of TMD. If we observe a statistically significant reduction in pain mediated feeding behavior, then we will submit a Phase II application to further develop this device for clinical testing in humans. PUBLIC HEALTH RELEVANCE: MicroTransponder aims to develop a novel, wireless, minimally-invasive microstimulator to treat craniofacial pain using subcutaneous electrical stimulation methods. The device will be injectable via hypodermic needle, fully biocompatible, and cost-effective for the majority of refractory patients of craniofacial pain. The innovation holds promise for vastly heightened efficacy while reducing the majority of safety risks and side- effects compared to existing pain management solutions.